Israel and Hamas on the brink of war after assassination of military leader

Israel and Hamas were on the brink of war today after Israeli air strikes in Gaza killed the head of Hamas's military wing and at least nine other Palestinians. Ahmed Said Khalil al-Jabari is the most senior Hamas official to be killed since the major Israeli offensive four years ago. He died in his car along with an aide as Israel launched more than 50 airstrikes across Gaza after days of rocket fire from the territory. Palestinian reports said 10 people died in the offensive, named Operation Pillar of Defence, including two children.

Hamas last night responded to the attacks by declaring that Israeli had "opened the doors of hell."

"The Israeli occupation has committed a dangerous crime and exceeded all red lines. This is considered to be a war and they will pay a high price."

Israeli prime minister Binyamin Netanyahu said that the killing of al-Jabari had sent a "clear message" to Hamas, adding: "if it becomes necessary we are prepared to expand the operation." In a statement on Twitter, the Israeli Defence Force said: "All options are on the table. If necessary, the IDF is ready to initiate a ground operation in Gaza."

In a telephone conversation with Netanyahu last night, Barack Obama reiterated US support for Israel's right to self-defence against rocket attacks from Gaza but urged Israel to avoid civilian casualties in the Palestinian territory. "The two agreed that Hamas needs to stop its attacks on Israel to allow the situation to de-escalate," the White House said.

An emergency meeting of the UN Security Council was held last night at the request of Egypt, Morocco and the Palestinians.

"Once again the international community is witness to Israel's malicious onslaught, using the most lethal military means and illegal measures against the defenceless Palestinian civilian population," the Palestinian Authority's UN envoy Riyad Mansour told the Council.

"A direct firm message must be sent to Israel to cease immediately its military campaign against the Palestinian people and to abide ... by its obligations under international law."

UN secretary general Ban Ki-moon told Netanyahu of his expectation that "Israeli reactions are measured so as not to provoke a new cycle of bloodshed that could cause additional civilian casualties and have dangerous spillover effects in the region," the UN said.

The British Foreign Office issued a statement saying: "We continue to call on all sides to exercise restraint to prevent a dangerous escalation that would be in no-one's interests."

Egypt, one of only two Arab countries to have a peace treaty with Israel, recalled its ambassador from the country and urged Arab leaders to take "decisive action".